Edwin Blancher was looking for a genealogical breakthrough.Researching his patrilineal family tree through documents revealed roots in Vermont. There he stumbled on the gravesite of his great, great grandfather William Blancher. Or was it Blanchard?

The 79-year-old retired postal worker from Canyon Country says he suspected his oldest known relative, whose headstone indicates he was born in 1790, could have altered the surname.

Six years ago, a pair of home DNA test kits would prove Blancher right and add 150 years of Blanchard branches to his family tree.

"Without DNA testing, I would have never known for sure," he says.

It's all in the genesEver since the descendents of slave Sally Hemings and Thomas Jefferson lit the fuse of DNA testing, curious people with $149 and enough enthusiasm to follow their bloodlines as far back as 400 years have become the fuel feeding this sweeping genealogical explosion.

DNA testing is the 21st century's most effective tool for blasting through barriers when the paper trail has run dry.

"Where we're missing a generation, we're able to connect two lineages and bridge the gap," says Bennett Greenspan, whose Houston-based company Family Tree DNA made genetic testing available to the public in 2000, ahead of its competitors.

DNA testing is still groundbreaking science among genealogy hobbyists like the 1,000 or so people expected Friday for the 38th annual Southern California Genealogy Jamboree and Resource Expo in Burbank.

The three-day event is one of the longest-running genealogical conferences on the West Coast. Between the big gatherings, genealogists stay busy.

Genealogy is purported to be the second most popular hobby in the U.S. after gardening — especially among aging Baby Boomers and their parents. A Google search is likely to bring up more than 32 million results, including a growing number of research databases such as Rootsweb.com, Ancestry.com and FamilySearch.com.

Greenspan owes the fascination to the cultural whitewashing experienced by early 20th century immigrants.

"There was a lot of pressure on people 100 years ago to become American, and the way you became American was you chopped off the last couple letters of your Jewish or your Italian name and you spoke English," he says. "Kids were embarrassed that their parents or grandparents spoke English with a funny accent. Conversely, parents and grandparents didn't speak to their children in their native tonguesbecause they wanted them to be Americans.

"Now we have generations of Americans that are disconnected from their European roots," he adds. "That becomes a real motivator for people to study their genealogy."

Most of the cotton-swab saliva tests now available look at the DNA markers on the Y chromosome found only in males and passed down from father to son.

The results can determine whether two people descend from the same ancestor. People can take the test along with suspected relatives they've identified on their own or just send in their single DNA sample and hope for a hit in one of the testing databases. They also can look for a surname project based on a match — or derivative — of their last name.

Male callThere are more than 4,000 surname projects already underway at Family Tree DNA, and the company has a database with 150,000 individual entries.

A 12-marker test is the standard for determining common ancestry.

Females, because they lack the Y chromosome, have a harder time with current DNA testing since it can only prove the ethnic and geographic origins of their direct female line. Those results are more anthropological than genealogical.

Some women go back two or three generations to find a male cousin they've never talked to just to ask him if he would be willing to take a DNA test.

Alice Fairhurst did.

The 70-year-old Covina woman has been working on branches of her family tree since 1954. She recalls her mother and aunts were always talking about their family, including her great grandmother Mary Matheson.

"They says she was born on Christmas Day in 1836, although I later found out she was born in January of 1837," Fairhurst says. "They would always talk about how much I was like her."

Naturally, it piqued her curiosity.

DNA testing was already widespread when Fairhurst met Gordon Matheson, who she thought was related.

It turns out they are not.

Matheson, in fact, shares no genetic material with any of the Scottish Matheson clan.

He's all Dunbar.

"It's mind boggling," says the 83-year-old Lakewood man who has been a member of the Matheson clan for decades and was recently welcomed into his newfound clan with open arms too. "You wonder what in the hell went on."

For others like Doug Miller, the 68-year-old former president of the Southern California Genealogical Society and Family Research Library in Burbank, DNA testing has put to rest long-held family lore.

"My Aunt used to tell me, 'You're descended from American Indians' and that was always in the back of my mind when I started my research 30 years ago," Miller says. "Of course, I was never able to verify that before. But through DNA testing, I know it's not on my paternal line and it's not on my maternal line."

And by year's end, an estimated 70,000 people could find the answers they're looking for too.